Transfer molding type power modules that include: a conductor plate (metal plate) laminated on and bonded to an insulating substrate; a power semiconductor element bonded to the conductor plate; wires that have electrical continuity with the power semiconductor element; a molded resin that covers these; and an insulating substrate (insulating layer) having a higher heat dissipation property than the molded resin have been proposed as power semiconductor devices (e.g., Patent Document 1).